Biology 3 Nov/Dec 2011 - Candidates Weakness

Biology Paper 3,Nov/Dec 2011

Questions:		1	2	4		Main

General Comments
Weakness/Remedies
Strength

Question 4
(a) (i) Identify the organism in the diagram. Identification………………………………………………………………………………………………………………… [1 mark ] (ii) Name the parts labeled I to X I. …………………………………………………………. VI. ………………………………………………………… II. ………………………………………………………… VII…………………………………………………………. III. ………………………………………………………… VIII………………………………………………………… IV. ……………………………………………………….. IX. …………………………………………………………. V. ………………………………………………………. X. …………………………………………………………. [ 5 marks] (iii) State the function of the parts labeled I,II,III,IV, and VII. I. …………………………………………………………………………………………………………………………….. II. …………………………………………………………………………………………………………………………….. III. ……………………………………………………………………………………………………………………………. IV……………………………………………………………………………………………………………………………… VII. …………………………………………………………………………………………………………………………… [ 5 marks ] (c) (i) List four observable features of the organism and state how they adapt the organism to its mode of life. ……………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………….. …………………………………………………………………………………………………………………………………….. …………………………………………………………………………………………………………………………………….. [ 8 marks ] (ii) State two ways in which the organism is of economic importance …………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… [2 marks ] (iii) State two ways by which the activities of the organism can be controlled. …………………………………………………………………………………………………………………………………. …………………………………………………………………………………………………………………………………. [ 2 marks ] (d) (i) State the class of the organism ………………………………………………………………………………………………………………………………….. [ 1 mark ] (ii) Give three reasons for placing the organism in the class named in 4(d)(i) above. …………………………………………………………………………………………………………………………………. …………………………………………………………………………………………………………………………………. …………………………………………………………………………………………………………………………………. [ 3 marks ] (e) State the: (i) Habitat: …………………………………………………………………………………………………………………… (ii) Diet: ……………………………………………………………………………………………………………………….. (iii) Type of metamorphosis undergone by the organism:……………………………………………. ………………………………………………………………………………………………………………………………. [ 3 marks ]
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COMMENT
This was also a popular question for the candidates and they scored high scores. Most candidates could properly identify the grasshopper and name the labeled parts. But some candidates, lost marks through spelling errors. In labeling the grasshopper some candidates added ‘s’ in labeling single structures e.g hind leg’s’ and so lost marks. Most candidates could also state the functions of the labeled parts however many candidates lost the score for spiracles as the wrote for respiration rather than gaseous exchange. Most candidates could state the control, habitat, diet and type of metamorphosis of the grasshopper as well as its class but areas of challenge include reasons for placing the organism in the class as well as structures which adapted the organism to its environment. The structures were not properly qualified e.g. mouth parts for feeding on vegetation rather than chewing mouth parts. And the characteristics of the phylum arthropoda were listed rather than for the class insect expected answers include: Adaptive features of Grasshopper - Chewing mouth parts/mandibles; for feeding on vegetation; - Presence of antennae; for sensitivity; - Possession of powerful hind legs; for hopping; - possession of short fore limbs/legs; which acts as a shock absorber for landing;. - possession of thickened fore wings; to protect the inner membranous wings; - chitinous exoskeleton; to prevent desiccation /mechanical injury; - (Green/brown) colour/camouflages; to blend with vegetation; - presence of spiracles; for breathing. Class of organism Insecta Reasons Three body divisions/head,thorax and abdomen. A pair of antenna three pairs/six appendages/walking legs